JPH0278948A - Deterioration damage detection device and detection method for metal materials - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method and apparatus for inspecting damage and deterioration of metal materials, and in particular to ferrite-containing metal materials used in the high temperature environments of atomic couplants and chemical plants. The present invention relates to a measuring device suitable for detecting high temperature aging embrittlement, strain damage, etc. in actual machine parts made of metal materials such as stainless steel and low alloy steel.

[Conventional technology]

An example of a conventional embrittlement measurement method is Japanese Patent Application Laid-Open No. 54-619.
There is a method as described in Publication No. 81. Here, it is assumed that the presence or absence of embrittlement in the austenitic stainless steel weld metal is determined based on a decrease in the initial amount of δ ferrite by 5% or more.

[Problem to be solved by the invention]

In the above conventional technology, among the metal materials used at high temperatures,
In particular, taking ferrite-containing stainless steel as an example, it is already known that aging embrittlement occurs when used at high temperatures for long periods of time. This is due to the precipitation of the σ phase at relatively high temperatures of approximately 600° C. or higher. σ embrittlement occurs, and in the range of 400°C to 500°C, so-called 475
This is due to the occurrence of °C brittleness. However, the 475℃ brittleness is
This may occur during long-term use even in a temperature range of 400''C or lower, and sufficient consideration must be given when using actual machine parts made of ferrite-containing stainless steel at high temperatures.

However, the above-mentioned conventional technology does not consider strain aging in the case of embrittlement at 500° C. or lower and pre-strain, and cannot detect the degree of -475° C. embrittlement.

In addition, the initial amount of ferrite in the welded part of an actual machine differs depending on the welding position, and the variation is large. Furthermore, in an actual machine, there are a huge number of welded parts, so it is difficult to monitor all the welded parts and the initial amount of ferrite in the equipment material. Therefore, the conventional technology cannot be applied to locations where the initial amount of ferrite is unknown, so there is a problem that it cannot be put to practical use in actual equipment.

On the other hand, the eddy current inspection method (Eddy Current Te5
An example of the ``Method'' (hereinafter referred to as ECT) is ``Method for determining the state of deterioration of iron-based alloys of strong precipitation effect type'' described in JP-A-55-141653. In this conventional example, the ECT value of the material to be measured is compared with the ECT value of the material to be measured before use, or a material of the same type that has been subjected to the same heat treatment as the initial heat treatment of the material to be measured, and the value is determined to be correct. This shows a method for determining the state of deterioration of an iron-based alloy based on whether it is negative or negative.

However, it is only determined based on the positive and negative values.

Quantitative measurements are not possible. Furthermore, no consideration is given to strain aging when there is pre-strain.

An object of the present invention is to provide a method and apparatus that can non-destructively and accurately detect the degree of brittleness and strain damage in metal material parts such as ferritic stainless steel and low-alloy steel used in high-temperature environments. It is about providing.

[Means for solving the problem] ゛゛The objective is to measure the magnetic properties of the material that change as the material deteriorates over time, and to determine the degree of material deterioration and strain damage from the ratio. be able to. The form of magnetic hysteresis indicating the magnetic properties of the material and the level of magnetic Barkhausen noise correspond well to the degree of material deterioration and strain damage. That is, the degree of deterioration and strain damage of the metal material can be estimated from this change.

In order to efficiently excite a local region of the object to be measured with a strong magnetic field, it is also possible to use a superconducting coil as the excitation coil.

In addition, in place of the detection coil and integrator, a superconducting quantum interference device (SQUI), which can perform high-precision magnetic measurement, is used to detect the magnetic field.
D) Alternatively, a magnetic sensor of a semiconductor Hall element may be used.

To estimate the degree of deterioration and damage of metal materials, saturation magnetism,
A high correlation can be obtained by applying statistical data processing such as multiple regression analysis to parameters such as residual magnetism, coercive force, magnetic Barkhausen noise level, and material data.

Kame Deterioration loss detection device of the present invention! i. In a metal material inspection apparatus that applies a magnetic field to a measurement object using an excitation coil or the like and detects deterioration or damage from changes in magnetism generated in the measurement object, the saturation magnetism of the measurement object, residual magnetism,
Equipped with a magnetic measurement device that detects magnetic properties such as coercive force and Barkhausen noise, and a calculation device that determines the state of the magnetic field in the measurement area using numerical analysis methods, the system is equipped with a magnetic measurement device that detects magnetic properties such as coercive force and Barkhausen noise, and a calculation device that determines the state of the magnetic field in the measurement area using numerical analysis methods. It is characterized by comprising an arithmetic device that determines the degree of strain damage or deterioration of a material from a database of relationships between changes in magnetic properties such as noise and damage or deterioration of metal materials, and a display device that outputs the output.

In this case, an exciting coil that excites the ΔIIJ constant body and 11
It is preferable to integrate a magnetic sensor that detects the magnetic characteristics of 1rJ regular holidays. In addition, an excitation coil that excites the object to be measured and a magnetic sensor that detects the magnetic properties of the object to be measured are placed between the object to be measured, and the leakage magnetic flux of the object to be measured is measured to determine strain damage and deterioration of the material, or It is preferable to use a horseshoe-shaped coil to detect the magnetic anisotropy of the measuring object to determine strain damage or deterioration of the material.

If the latter determination method is adopted, one idea would be to rotate a horseshoe-shaped excitation coil to measure magnetic anisotropy, and determine strain damage or deterioration from the directions and values of maximum and minimum magnetism. Other determination methods include: ■ A method for determining strain damage and deterioration from magnetic properties, using the measured r
Assuming a certain amount of strain for the 3-H characteristic, B- measured from the aging database at that strain amount
The B-H characteristic closest to the H characteristic is selected, the aging time is determined, and then, based on this aging time, 1lli + determined B-
Select the B-H characteristic that is closest to the H characteristic, re-determine the strain amount, change the strain amount to J, t, and l, and repeat the above method in the same way, and the final converged strain is the aging time. A method for determining the strain loss G and deterioration of the object to be measured.■ Change the output of the excitation coil in stages, calculate the magnetic characteristics in the depth direction of the object to be measured from the amount of change, and calculate the magnetic properties in the depth direction of the object to be measured. A method for determining strain damage and deterioration based on magnetic properties: Assuming a certain amount of strain on the measured Barkhausen noise spectrum, and measuring from the aging database at that strain amount. Select the Barkhausen noise spectrum that is closest to the Barkhausen noise spectrum determined by Select the closest Barkhausen noise spectrum, re-determine the new strain amount, repeat the above method using the strain amount as a reference, and finally calculate the converged strain amount and aging time to determine the strain damage and the aging time of the measurement object. Method for determining deterioration, ■As a method for determining strain damage and deterioration from magnetic properties, from data such as coercive force, residual magnetism, and magnetic hysteresis loop area of measured B-H characteristics,
An effective method is to use a database of magnetism, damage, and deterioration determined in advance through statistical processing to determine strain damage and deterioration of the measuring object.

Structurally, the excitation coil and magnetic sensor are arranged in an array system, and a dummy excitation coil is provided at the outermost periphery to ensure uniformity of the magnetic field.

■ Alternately arranging the directivity of the excitation coil and magnetic sensor in orthogonal directions, and ■ Using a superconducting quantum interference device (SQUID) sensor as the magnetic sensor.

It is preferable to use a pickup coil structure of a 5QUID sensor capable of detecting magnetic anisotropy.

In addition, when determining the magnetic characteristics of a wall such as a reactor pressure vessel by 1 llq, an excitation coil and a drive device for scanning a magnetic sensor are placed on the inner wall and the outer wall, respectively, and the excitation coil is placed on the inner wall and the magnetic sensor is placed on the outer wall, or the magnetic sensor is placed on the inner wall. It is effective to place an excitation coil on the sensor and outer wall. When measuring the magnetic properties of piping, an excitation coil and a drive device that scans the magnetic sensor are placed inside and outside the piping, respectively, and the excitation coil is placed inside the piping.

It is effective to arrange a magnetic sensor outside the pipe, or a magnetic sensor inside the pipe, and an excitation coil outside the pipe.

Furthermore, from the measured damage and deterioration data of the measured object and the database of equipment for the measured object, it is possible to have a function to predict future damage and deterioration of the measured object from the deterioration database, and to predict damage and deterioration of the measured object in the future. The screen of the display device that displays the state of deterioration is divided into multiple sections, and the 8I constant conditions and measured magnetic properties are displayed.

Displays the usage environment and material data of the equipment to be measured, data on determined damage and deterioration, and predictions of future damage and deterioration progression of the equipment, etc., and allows data to be entered and corrected using the mouse or keyboard as necessary. It is also effective to have a functional unit that can re-revise judgments and calculations.

[Effect]

When metal materials are used in high-temperature environments for long periods of time, their internal structure changes and their strength decreases. Looking at the Charpy impact test results of aged ferrite-containing stainless steels heat-treated at 475°C, it can be seen that the strength decreases as the high-temperature aging heat treatment time increases.

As a result of various studies on the embrittlement caused by high-temperature heating of metal materials such as ferritic stainless steel, the inventors found that other phases precipitate at the grain boundaries of the metal structure due to high-temperature aging, and that carbides, S, and P It was found that due to the segregation of , not only mechanical properties such as hardness and impact strength but also electromagnetic properties such as electrical resistivity ρ and magnetic permeability μ change. In particular, we found that high-temperature aging embrittlement of materials corresponds well to changes in magnetic properties. The measurement results of magnetic hysteresis of the received material and the high-temperature heat-treated material show that the area of the magnetic hysteresis loop (magnetic hysteresis loss), residual magnetism, coercive force, etc. change depending on the degree of embrittlement of the filq fixed material. Furthermore, when measuring the magnetic Barkhausen noise generated when a metal material is excited, a difference is seen in the components of the magnetic Barkhausen noise level between the received material and the high-temperature heat-treated material.

Also, when plastic strain is applied to metal materials such as ferritic stainless steel or low alloy steel due to processing.

The magnetic properties of the material change depending on the amount of plastic strain. Furthermore, when a pre-strained material was aged, a similar change in magnetic properties was obtained that corresponded to the degree of strain aging.

That is, by utilizing such a phenomenon, it is possible to accurately detect processing strain and the degree of aging embrittlement of metal materials such as ferritic stainless steel and low alloy steel.

〔Example〕

Next, an embodiment of the present invention will be described based on the drawings.

The relationship between strain damage and aging deterioration of the metal material of the measuring body 1 and magnetic properties, which is the principle of the present invention, will be explained using the drawings.

FIG. 20 shows a magnetic hysteresis loop when plastic strain is applied to duplex stainless steel. Comparing plastic strain i p=o% and 1p=2%,
The shape of the magnetic hysteresis loop changes due to plastic strain, and an increase in the maximum magnetic flux density and residual magnetic flux density is observed.

However, the coercive force has hardly changed.

FIG. 21 shows changes in residual magnetic flux density due to plastic strain in the two-phase stainless steel CF3M material and CF8M material. As shown in the figure, as the plastic strain increases, the residual magnetic flux density increases rapidly, but as the plastic strain increases, the residual magnetic flux density tends to saturate. The CF3M material and the CF8M material have the same tendency of change in residual magnetic flux density depending on the amount of plastic strain, but there are some differences in their absolute values.

FIG. 22 shows the relationship between the amount of plastic strain and coercive force for the above materials. From the figure, the coercive force shows an almost constant value regardless of the plastic strain, that is, the plastic strain has no effect on the coercive force.Figure 23 shows the amount of plastic strain and the maximum magnetic flux for the above materials. This shows the relationship between density. As shown in the figure, there is a slight increase in the maximum magnetic flux density by applying plastic strain, but the maximum magnetic flux density shows a nearly constant value regardless of the amount of plastic strain.

Figure 24 shows the magnetic properties (B-H characteristics) in the direction parallel to the direction of applying plastic strain when plastic strain is applied to a metal material.
This figure shows the magnetic characteristics (B-H characteristics) in the direction orthogonal to . Due to plastic deformation, the magnetic domains in the material align in the plastic strain direction, creating magnetic anisotropy in parallel and orthogonal directions. Therefore, the B-H characteristic (B//
The BH characteristic (B earth f'p) in the direction orthogonal to εp) decreases.

FIG. 25 shows magnetic anisotropy data arranged in terms of the relationship between the maximum magnetic flux density Bp, the residual magnetic flux density Br, and the strain me. That is, the strain state can be determined from the magnetic properties in the direction parallel to and orthogonal to the plastic strain.

Using these characteristics as a database, strain damage in metal materials can be determined.

Next, the relationship between aging deterioration of metal materials and magnetism will be explained based on the drawings.

FIG. 26 shows the change in Charpy absorbed energy with aging of duplex stainless steel. As the aging time increases, the Charpy absorbed energy decreases. Therefore, in order to non-destructively measure this change, we investigated the relationship between aging and magnetic properties.

An example thereof is shown in FIG. In contrast to the magnetic hysteresis loop of virgin material, the magnetic hysteresis loop of aged material is
It can be seen that although the maximum magnetic flux density hardly changes, the residual magnetic flux density, coercive force, and magnetic hysteresis loop area increase.

Next, the magnetic properties (B-H characteristics) of the virgin material and aged material of the duplex stainless steel material when a plastic strain εp = 2% is applied.
An example of this is shown in FIG. Plastic strain 1p=o% and 2%
When comparing the virgin material of , the shape of the magnetic hysteresis loop changes due to plastic strain, and an increase in the maximum magnetic flux density and residual magnetic flux density is observed. However, the coercive force has hardly changed. When this plastic strain EP: 2% material is aged, a change in the shape of the magnetic hysteresis loop is observed due to aging, and the magnetic hysteresis loop area, residual magnetic flux density, and coercive force increase, as shown in FIG. However, the maximum magnetic flux density has hardly changed. This suggests that the effects of plastic strain on the magnetic properties and the effects of aging on the magnetic properties are due to different mechanisms. That is, the magnetic domains have anisotropy in the plastic strain direction due to plastic deformation, so the magnetic permeability increases and the maximum magnetic flux density increases. Furthermore, during aging, the rotational moment of the magnetic domain increases due to the precipitation of α' phase, G phase, etc. within the magnetic ferrite phase, and it is considered that the residual magnetic flux density and coercive force increase.

FIG. 28 shows the change in coercive force due to plastic strain. In a virgin material, the coercive force is constant regardless of plastic strain.

In aged materials, the coercive force increases as the plastic strain increases, but it tends to reach saturation. Moreover, the longer the aging time, the greater this tendency.

FIG. 29 shows the data in FIG. 28 organized by statute of limitations. From the figure, the coercive force of the virgin material is .

Although it was almost constant regardless of the amount of plastic strain, it showed a tendency to increase almost linearly with respect to the logarithm of aging time.

When the plastic strain εp is 0.2% or less, no effect of the plastic strain is observed. In the range of plastic strain fp=0.2% to 2%, there was a tendency that the larger the plastic strain, the larger the change in coercive force. Furthermore, at plastic strain εp=2% or more, the influence of plastic strain tended to be saturated.

Figure 30 shows the change in residual magnetic flux density due to plastic strain.The residual magnetic flux density increases as the plastic strain increases;
It tends to become saturated. Moreover, the longer the aging time, the greater this tendency.

FIG. 31 shows the data in FIG. 30 organized by statute of limitations. From the figure, the residual magnetic flux density showed a tendency to increase almost linearly with respect to the logarithm of the aging time. Furthermore, the larger the amount of plastic strain, the larger the residual magnetic flux density appeared.

Figure 32 shows the change in maximum magnetic flux density due to plastic strain. The maximum magnetic flux density increased rapidly when plastic strain was applied, but it remained almost constant regardless of the amount of plastic strain. The maximum magnetic flux density increased by approximately 50% in a test piece in which plastic strain was applied to a material with a plastic strain of ε220%. Moreover, no change in the maximum magnetic flux density was observed after one aging.

FIG. 33 shows the data in FIG. 32 organized by statute of limitations. It can be seen that the maximum magnetic flux density does not change depending on the aging time.

FIG. 34 shows the magnetic hysteresis loop when plastic strain is applied to low alloy steel. Comparing plastic strain 1p=o% and εp=4%, the shape of the magnetic hysteresis loop changes due to plastic strain, and an increase in coercive force and residual magnetic flux density is observed. However, the maximum magnetic flux density has hardly changed.

The operating principle of the present invention will be explained using FIG. 34.

When metal materials are used in high-temperature environments for long periods of time, their internal structure changes and their strength decreases. FIG. 34 shows the results of a Charpy impact test of an aged material of ferrite-containing l-based stainless steel rust that was heat-treated at 475°C. The strength decreases as the heat treatment time increases during high twist aging.

As a result of various studies on the embrittlement caused by high-temperature heating of metal materials such as ferritic stainless steel, the inventors found that other phases precipitate at the grain boundaries of the metal structure due to high-temperature aging, and that carbides, S, and P Due to segregation, hardness and f! #It was found that in addition to mechanical properties such as impact strength, electromagnetic properties such as electrical resistivity ρ and magnetic permeability μ change. In particular, we found that high-temperature aging embrittlement of materials corresponds well to changes in magnetic properties. According to the measurement results of magnetic hysteresis of received materials and high-temperature heat-treated materials, the area of the magnetic hysteresis loop (magnetic hysteresis loss) depends on the degree of embrittlement.
, changes have occurred in residual magnetism, coercive force, etc. Furthermore, when measuring the magnetic Barkhausen noise generated when a metal material is excited, a difference is seen in the components of the magnetic Barkhausen noise level between the received material and the high-temperature heat-treated material.

Furthermore, when plastic strain is applied to a metal material such as ferritic stainless steel or low alloy steel by processing, the magnetic properties of the material change depending on the amount of plastic strain. Furthermore, when a pre-strained material was aged, a similar change in magnetic properties was obtained that corresponded to the degree of strain aging.

That is, by utilizing such a phenomenon, it is possible to accurately detect processing strain and the degree of aging embrittlement of metal materials such as ferritic stainless steel and low alloy steel.

FIG. 35 shows the change in the amount of plastic strain and coercive force in low alloy steel. From FIG. 6, as the plastic strain increases, the coercive force increases rapidly.

As the plastic strain increases, the coercive force tends to saturate. When this material is aged, the coercive force decreases, but remains constant regardless of the aging time.

FIG. 36 shows changes in the amount of plastic strain and residual magnetic flux density in low alloy steel. This is the same result as the coercive force in FIG. 35.

FIG. 37 shows changes in Charpy absorbed energy with aging of low alloy steel. The change in Charpy absorbed energy with increasing aging time is small.

Therefore, in order to non-destructively measure changes in aging and plastic strain, we investigated the relationship between magnetic properties. -Example No. 38
and FIG. 39.

FIG. 38 shows the change in coercive force of low alloy steel with increasing aging time. In a virgin material, if there is one aging that allows the plastic strain to be determined by the coercive force, the plastic strain ε
Although p=1% or less can be determined, plastic strain i p=
At 1% or more, the coercive force is.

It becomes a constant value.

FIG. 39 shows the change in residual magnetic flux density of low alloy steel as the aging time increases. In virgin material, plastic strain can be determined by the residual magnetic flux density. If there is a statute of limitations,
Plastic strain 1p = 0.2% or less or εp = 0.5
% or more can be determined.

In this way, in duplex stainless steel and low alloy steel, 1
A close correlation was observed between M strain and aging and changes in magnetic properties.

Next, an embodiment of the system of the present invention will be described with reference to the drawings.

Figure 1 shows an example of a system configuration for implementing the metal material deterioration inspection apparatus according to the present invention. In Figure 1, 1 is a measurement object such as equipment or piping used in an atomic couplant, etc. .

21 is an excitation coil for exciting the measurement object 1;
22 is a magnetization device for the excitation coil 21.

31 is a magnetic sensor for detecting the magnetism of the measurement object I, and 32 is a controller for the magnetic sensor 31. 4
1 is a drive device for the excitation coil 21 and magnetic sensor 31;
2 is the drive device i! 41 controller. 51 is an excitation controller 22° magnetic sensor controller 32
This is a magnetic calculation device that inputs and analyzes data from the drive controller 42 and the drive controller 42. 52 is a magnetic database of the measurement object 1. 61 is a deterioration calculation device that determines the degree of deterioration of the measuring object based on the data analyzed by the magnetic calculation device 51. 62 is a database showing the relationship between the magnetism of the measurement object 1 and the degree of deterioration. 71 is a display device that outputs the determination result of d(d).

In the operation of the system of the present invention, first, the above-mentioned 8 (regular holiday 1) is excited by the excitation coil 21, and the magnetic change at this time is detected by the magnetic sensor 31.The details of the embodiment of this sensor section are shown in FIG. This will be explained using FIG.

FIG. 2 shows an excitation coil 21 inside a core 211 with a coaxial structure.
0 is arranged and the measurement object 1 is excited. The central core contains magnetic sensors 3 such as Hall elements and detection coils.
10 is arranged to detect magnetic changes in the measurement object 1.

FIG. 3 shows a magnetic sensor 310 such as a Hall element or a detection coil arranged in the embodiment shown in FIG. 2 on the opposite side of the exciting coil 210 with respect to the closed day 1. Magnetic changes in the book body 1 are detected by leakage magnetic flux.

4 and 5 show a sensor for detecting the magnetic anisotropy of the 31'l constant body 1. FIG. In FIG. 4, an excitation coil is wound around a horseshoe-shaped core 212, and the ii+11 constant body 1 is transformed into a moving body 1. The magnetic sensor 310 detects the leakage magnetic flux on the surface at this time.
Detect with. In FIG. 5, the magnetic sensor 310 in the embodiment of FIG. 4 is placed on the opposite side of the excitation coil 210 with respect to the measuring object 1. In FIG. The magnetic change in the measurement object 1 is detected from the leakage magnetic flux on the opposite side of the excitation coil 210.

Further, in order to improve the measurement efficiency, an embodiment in which the excitation coil 21 and the magnetic sensor 31 are arranged in an array system is shown in FIGS. 6 and 7.

FIG. 6 shows an embodiment of a -dimensional array type sensor section. excitation coils 213 whose magnetic measurement directions are orthogonal to each other;
214 and magnetic sensors 313 and 314 are arranged in one dimension, and a dummy excitation coil 215 is provided at the extreme end for correcting disturbances due to magnetic diffusion. By scanning this array type sensor, the magnetic characteristics of the measuring object 1 can be detected at high speed.

FIG. 7 shows an embodiment in which the one-dimensional array type sensor shown in FIG. 6 is extended to two dimensions. Magnetism) l (1 Excitation coils 213, 214 whose fixed directions are orthogonal to each other and the magnetic sensor 31
3,314 are arranged two-dimensionally, and a dummy excitation coil 21 is provided on the outer periphery to correct disturbances caused by magnetic diffusion.
There are 5. By scanning this two-dimensional array type sensor, the magnetic characteristics of the measuring object 1 can be detected even faster.

Figure 8 shows a superconducting quantum interference device (SQU) in a magnetic sensor.
ID) This is an example using a sensor.

Liquid He is injected into a cryostat 333 that can measure an external magnetic field by applying a 5QUTD sensor that is generally used for biological examinations, etc., and is maintained at a temperature at which the 5QtJ4D sensor 330 operates. The 5QUID sensor 330 is inside a magnetic shield 334 that blocks noise. The magnetic signal is detected by a pickup coil 331. The pickup coil 331 is composed of elliptical coils arranged orthogonally to each other in order to detect magnetic anisotropy, and is designed to detect a difference in magnetic anisotropy. Also, Fig. 9 and 1
Figure 0 shows another embodiment of the pickup coil. In FIG. 9, a second-order differential coil is formed coaxially. Magnetic distribution can be detected with high precision. FIG. 10 shows an arrangement in which two or more differential coils are arranged in parallel, and the magnetic distribution can be detected with high precision.

An embodiment in which details of the wA control device 41 for scanning the excitation coil 21 and magnetic sensor 31 shown in FIG. 1 are applied to a boiling water reactor will be described with reference to FIGS. 11 to 16.

FIG. 11 is a cross-sectional view of a boiling water reactor.

610 is a reactor pressure vessel, 611 is a control rod, 612 is a control rod guide tube, 613 is an upper lid, 614 is a reactor core support, and 615 is reactor water. A crane 617 is located in a portion of the reactor pressure vessel 610.

The drive device 41a is connected to the crane 617 by a cable 900.
has been lowered, and 6 is in the reactor water of the reactor pressure vessel 610.
A drive device 41a is disposed on the inner wall of 15. The drive device 4La is connected via a cable to a monitor 618 and the like placed outside the reactor pressure vessel 610, and is operated by remote control.

Further, a drive device 41b is arranged on the outer wall of the reactor pressure vessel 610, and the drive device 41b has a rail 620 instead of the cable 900 and moves on a track. Drive device 4
1a and 41b can be linked to inspect the reactor pressure vessel 610 by remote control.

FIG. 12 is an example of an X-Y scanning type driving device for inspecting a reactor pressure vessel. The drive device 41 includes a frame 891. which has four pillars. A suction cup 892 for fixing to the wall of the reactor pressure vessel 610, a vacuum pump 893, a motor 895 for moving the frame 891 on the X axis, and a gearbox 8
96 and a drive shaft 898, a motor 897 for moving on the Y axis, an air cylinder 899 equipped with a gear box, and a drive shaft 894, and the tip of the air cylinder 899 is equipped with an excitation coil 21 and a magnetic sensor 31. be.

Another example in which the present invention is applied to a piping system of a boiling water nuclear reactor will be described with reference to FIGS. 13 and 14.

FIG. 13 is an example of a drive device for external inspection of the reactor piping system. The drive device R41 includes a fixing ring 81 that can be divided into two parts.
0 and a rotating ring 811 that can rotate in the circumferential direction of the pipe 630
Consisting of The fixed ring 810 includes a drive motor 820,
Gear box 821 and position detection encoder 82
There are three sets of axial movement mechanisms consisting of 7. The amount of axial movement is detected by a roller 824 and an encoder 826, and the 0-rotation ring 81 is fed back to the axial movement mechanism.
1 is a rotary motor 8 that is held on a fixed ring 810 by a plurality of pulleys 825 and has a circumferential position detection function.
It is driven by 23. A head section 85 equipped with an excitation system 2 and a magnetic sensor system 3 on a part of the rotating ring 811
There is 0. The drive motors 820 and 823, the encoders 826 and 827 degrees, and the head section 850 are provided with magnetic shields to prevent magnetic noise from affecting magnetic measurements.

FIG. 14 is an example of a drive device for inspecting the inside of a reactor piping system. The drive device 41 includes a drive system for moving inside the pipe and a scanning system for scanning the sensor section.

In the drive system, the signal is transmitted to each driving wheel via a timing belt 922 by a stepping motor or the like 910.

Allows the device to be moved within the piping.

In the scanning system, the signal is transmitted to a shaft 923 by a stepping motor or the like 925, via repulleys 924, 928, and a timing belt 926.

The magnetic sensor section at the tip of the shaft 923 is scanned.

The magnetic sensor section includes an excitation coil 21 and a magnetic sensor 31, and is pressed against the object to be measured using an air cylinder 931 or the like during measurement.

By combining the drive devices shown in FIGS. 12 to 14, the measurement methods shown in FIGS. 3 and 5 become possible.

As mentioned above, the excitation coil 21. The magnetic sensor 31 and the drive device 41 measure the measurement object 1 of a nuclear power plant, etc.
can detect the magnetic properties of

Next, two examples of measurement methods will be described.

The first method is to detect the magnetic properties of the measuring object 1 in the thickness direction. Increase the output of the excitation coil in stages,
Changes in magnetic properties are measured by varying the degree of penetration of magnetic flux in the depth direction. Information in the depth direction is obtained from the difference between two pieces of magnetic property data. Furthermore, it can be similarly determined by changing the frequency of the excitation coil and changing the penetration depth of the magnetic field.

The second method is to detect the magnetic anisotropy of the measurement object 1. Using the excitation coil shown in FIG. 4 or 5, the magnetic characteristics of the measuring object at all angles can be measured, and the magnetic anisotropy can be determined from the directions of maximum and minimum sensitivity and the angular distribution of magnetism.

In FIG. 1, excitation coil 21. The measurement data of the magnetic sensor 31 and the drive device 41 is sent to each controller 22.
, 32, and 42 to the magnetic arithmetic unit 51.

FIG. 15 shows details of the magnetic calculation device 51.

Measuring object 1? 1l11 constant excitation coil 21. Magnetic sensor 31. and the data of the drive device 41 are stored in the magnetic calculation device 5.
1 input memory 511. input memory 51
The measurement data of No. 1 is output to the magnetic data display device 512, and the measurement status is checked. Further, the basic magnetic data of each material is imported from the magnetic database 52.

After checking the d111 steady state and measurement data, the M field is analyzed by the magnetic field analysis calculation device 513. The analysis method is selected from the magnetic field analysis code 514.

From the results of the magnetic field analysis, anisotropy data processing 517 that separates anisotropy data of magnetic properties and depth direction data processing 516 that separates depth direction data of magnetic properties are performed to achieve the above-mentioned results. The data will be processed as follows.

These data are input to the deterioration calculation device.

FIG. 16 shows details of the deterioration calculation device 61.

The anisotropy and depth direction data of the magnetic properties obtained from the magnetic field analysis are loaded into memories 561 and 562, respectively.

The data on the anisotropy of the magnetic properties is subjected to preprocessing for deterioration determination in the magnetic anisotropy data preprocessing 563.

Parameters are selected in order of highest correlation.

Similarly, magnetic depth data preprocessing 564 performs deterioration determination preprocessing for magnetic depth data, and parameters are selected in order of highest correlation. These deterioration parameters are taken into the deterioration determination calculation process 565, and the degree of deterioration of the measurement object 1 is determined.

In addition, the database for determining deterioration is shown in Figures 20 to 42.
It has the data shown in the figure.

A detailed example of the strain aging deterioration determination performed by the deterioration determination calculation procedure 565 will be described with reference to FIGS. 40 and 41.

For a material that has undergone certain plastic strain and aging, the plastic strain and aging time can be quantitatively separated using the results shown in FIGS. 40 and 41. for example.

Assuming that the measured residual magnetic flux density Br is 4500 a, from Fig. 48, the aging time is 100 at a plastic strain of 4%.
hr, a plastic strain of 0.5% and an aging time of 200 hr, or a plastic strain of 0.2% and an aging time of 400 hr. Here, when the plastic strain is 4% and the aging time is 100 hours, the coercive force Hc is 370e from Figure 49.
becomes. Similarly, the aging time was 200 at a plastic strain of 0.5%.
In the case of h r.

When the coercive force He is 430e, the plastic strain is 0.2%, and the aging time is 400 hr, the coercive force Hc is 540e. Therefore, plastic strain and aging time are separated depending on the magnitude of residual magnetic flux density Br and coercive force He. The amount of plastic strain and aging time of duplex stainless steel can be determined from the residual magnetic flux density and coercive force.

Examples of FIGS. 17 and 18 are shown as examples of other determination methods.

FIG. 17 shows how the degree of deterioration due to strain aging is determined from the shape of the magnetic hysteresis loop.

Assuming the initial strain sensitivity, the closest magnetic hysteresis loop is found among the degrees of aging at that strain amount, and the aging time is determined.

Next, the closest magnetic hysteresis loop is found from among the amounts of strain during this aging time, and the amount of strain is determined.

Furthermore, assuming this amount of strain, a similar determination is made to determine the converged amount of strain and aging time.

FIG. 18 shows the same determination method as in FIG. 17 for the Barkhausen noise spectrum.

Furthermore, the current state of deterioration is determined from the obtained data, and the usage conditions are taken into consideration from the equipment database. By interpolating and extrapolating, future progress of deterioration is predicted and calculated.

Using this method, strain aging can be determined and future progress of deterioration can be estimated.

FIG. 19 shows details of the display device 71.

The screen of the display device 71 is divided into four parts, and the magnetic inspection measurement state 1
Device data, deterioration degree judgment status, and future deterioration degree progressor side are displayed, and each condition can be selected, modified, etc. using the mouse 72 on the screen.

According to these examples, the degree of strain aging can be determined with high precision from changes in the magnetic properties of the material, so that it is possible to improve the evaluation of material deterioration.

〔Effect of the invention〕

According to the present invention, the degree of embrittlement and the amount of plastic strain of metal materials used at high temperatures can be detected non-destructively and quickly, making it possible to prevent damage to equipment and improve the safety of actual equipment. can be increased.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an embodiment of the present invention. 2, 3, 4, and 5 are side views showing the details of the magnetic sensor section, and FIGS. 6 and 7 are perspective views showing the details of the array type magnetic sensor, respectively. Figure 8 is a cross-sectional view showing an example in which a 5QUID sensor is used as a magnetic sensor; Figure 9;
FIG. 10 is a perspective view showing an example of a pickup coil of a 5QUID sensor, FIG. 11 is a schematic cross-sectional view when the present invention is applied to a nuclear reactor inspection device, and FIG.
FIG. 3 is a perspective view of an X-Y scanning drive device used in the illustrated example. FIG. 13 is a partial perspective view of the piping system external inspection device,
Figure 14 is also a side view of the piping system internal inspection device,
FIG. 5 is a flowchart showing an example of the operation of the magnetic arithmetic device, No. 16.
17 is a flowchart showing an example of the operation of the deterioration calculation device, FIG. 17 is a relationship diagram of measurement data used for determining damage, FIG. 18 is a relationship diagram of measurement data used for determination of deterioration, and FIG. A plan view showing an example of a display device, FIGS. 20 and 21,
Fig. 22, Fig. 23, Fig. 24, and Fig. 25 are characteristic diagrams showing changes in magnetic properties due to plastic strain of duplex stainless steel, Fig. 26, Fig. 27, Fig. 28, and Fig. 29, respectively. , FIG. 30, FIG. 31, FIG. 32. Fig. 33 is a characteristic diagram showing changes in mechanical properties and magnetic properties regarding strain aging of duplex stainless steel;
Figures 35, 36, and 37. Figures 38 and 39 are characteristic diagrams showing changes in mechanical properties and magnetic properties regarding strain aging of low alloy steel, respectively.
41 and 42 are characteristic diagrams for aging time to explain the strain characteristic estimation method, respectively. 1... 11111 fixed bodies such as equipment or piping used in atomic couplants, etc., 21... Excitation coil, 22.
・・Excitation controller, '31 ・・Magnetic sensor, 32
... magnetic sensor controller, 41 ... drive device,
42... Drive device controller, 51... Magnetic calculation device, 52... Magnetic property database, 61... Deterioration calculation device, 62... Database showing the relationship between the magnetism of the measurement object 1 and the degree of deterioration. °S, 71...Display device, 72...
・Mouse, 210...excitation coil, 211...same l
1IIk structure core, 212...horseshoe-shaped core, 21
, 3', 214... Excitation' coil whose magnetic measurement directions are orthogonal to each other, 215... Dummy excitation coil, 310
...Magnetic sensors such as Hall elements and detection coils, 313
, 314... Magnetic sensor whose magnetic measurement directions are orthogonal to each other, 330... 5QUID sensor, 331... Pick-up coil, 332... Refrigerant such as liquid helium,
333... Cryosut that can measure external magnetic fields, 3
34... Magnetic shield, 511... Input memory, 5
12... Magnetic data display device, 513... Magnetic field analysis calculation device, 514... Magnetic field analysis code, 516...
depth direction data processing, 517... anisotropic data processing, 561... anisotropic data memory, 562...
Depth and direction data memory, 563...Magnetic anisotropy data preprocessing, 564...Magnetic depth data preprocessing, 56
5... Deterioration determination calculation procedure, 610... Reactor pressure vessel, 611... Control rod, 612... Control rod guide tube,
613... Upper grid, 614... Core support, 615... Reactor water, 617... Crane, 618...
...Monitor, 620...Rail, 630...Piping, 810...Fixing ring that can be divided into two, 810...
Fixed ring that can be divided into two, 811...Rotating ring, 8
20... Drive motor, 821 river gearbox 61.8
23...Rotary motor with position detection function, 824...
...Roller, 825...Pulley, 826...Encoder, 827...Position detection encoder, 850...
... Head part, 891 ... Frame with four pillars, 892 ... Suction cup, 893 ... Vacuum pump, 894
... Drive shaft, 895 ... X-axis motor, 896
... Gear box, 897 ... Y-axis motor, 898
...t%IuJlt shaft, 899 ・Air cylinder with gearbox, 900 ... Cable, 91
0...Stepping motor etc., 922...Timing belt, 923...Shaft, 924...Pulley, 925...Stepping motor etc., 926...
Timing belt, 928... Pulley, 931.
··Air cylinder. Agent: Patent attorney Katsuma Ogawa. No./7 210-=Excitation 8th section coil 211---Core 6/5---Menoto-Futomi 6/7・-7 Shi-shi 61δ91. E-niter 620...shi-ru 900--pouvre father-in-law, 12 mouth 898...shi-v7L 399--work completed 1st 130. 510-, - circular milling 871-, - rotating link 824...roller 8.50. ,,Hend No. 74 910.925---Ste Novin 7-Soichig'? 22
926-,,Timey/Re-N Ruto 75th day early /6th day 17th day 78th day /? ffi Chestnut 20I71 No. 21 Mouth of life! time t
(Kl) 27th Aging Material 28th c O/234 and r (% Ji No. 29 Kuchi Hc 473°C Shikari Ginpo t (mu) No. 30 Kuchi v O/234 Drunkness (Ji No. 31 Kuchi 47! ;”c E Mine effect H! tl'r t (Su No. 3
2 圀0/234 ε (%,) 33rd KoBP (1 elbow ff1) 34th TZ] 3rd! ffi 36th day type 6zu7? ! εr (system) 37th day ap 475″Ct=A・puu binding effect Makima t (mu) 38th
Kubu 392 47.5'CBFr#F1%vl t (6,
) No 40 0 47.5°C Aki's PrMt value

Claims (1)

[Scope of Claims] 1. In a metal material inspection apparatus that applies a magnetic field to a measurement object using an excitation coil or the like and detects deterioration or damage from magnetic changes generated in the measurement object, Equipped with a magnetic measurement device that detects magnetic properties such as saturation magnetism, residual magnetism, coercive force, and Barkhausen noise, and an arithmetic device that determines the state of the magnetic field in the measurement area using numerical analysis methods, , an arithmetic device that determines the degree of strain damage or deterioration of a material from a database of relationships between changes in magnetic properties such as coercive force and Barkhausen noise and damage or deterioration of metal materials, and a display device that outputs the information. A deterioration damage inspection device for metal materials characterized by: 2. An apparatus for detecting deterioration and damage to metal materials according to claim 1, characterized in that an excitation coil that excites the object to be measured and a magnetic sensor that detects the magnetic properties of the object to be measured are integrated. 3. In claim 1, an excitation coil that excites the object to be measured and a magnetic sensor that detects the magnetic properties of the object to be measured are arranged sandwiching the object to be measured, and the leakage magnetic flux of the object to be measured is measured. A deterioration damage detection device for metal materials, characterized by determining strain damage and deterioration of metal materials. 4. An apparatus for detecting deterioration damage of a metal material according to claim 1, characterized in that the excitation coil has a horseshoe shape to detect the magnetic anisotropy of the object to be measured to determine strain damage or deterioration of the material. 5. The metal according to claim 1, wherein the excitation coil and the magnetic sensor are arranged in an array manner, and a dummy excitation coil is provided at the outermost circumference in order to ensure uniformity of the magnetic field at the outermost circumference. Material deterioration damage detection device. 6. An apparatus for detecting deterioration and damage to a metal material according to claim 5, characterized in that the directivity of the excitation coil and the magnetic sensor are alternately arranged in orthogonal directions. 7. Deterioration of a metal material according to claim 1, characterized in that a superconducting quantum interference device (SQUID) sensor is used as an excitation sensor, and a pick-up coil structure of the SQUID sensor that can detect magnetic anisotropy is used. Damage detection device. 8. In claim 1, the output of the excitation coil is changed stepwise, and the magnetic characteristics in the depth direction of the measurement object are determined from the amount of change, and the strain damage and deterioration in the depth direction of the measurement object are determined. A deterioration damage detection device for metal materials, characterized in that it determines: 9. The metal according to claim 4, wherein in order to measure magnetic anisotropy, a horseshoe-shaped excitation coil is rotated, and strain damage and deterioration are determined from the direction and value of maximum magnetism and minimum magnetism. Material deterioration damage detection device. 10. As a method for determining strain damage and deterioration from magnetic properties, a certain amount of strain is assumed for the measured B-H characteristics, and the best value for the B-H characteristics measured from the aging database at that strain amount is Select the closest B-H characteristic,
Determine the aging time, then, based on this aging time, select the B-H characteristic closest to the B-H characteristic measured from the database of strain amounts at this aging time, and re-determine the new strain amount, A method for detecting deterioration damage in a metal material, comprising repeating the above method based on the amount of strain, and determining strain damage or deterioration of the measuring object based on the finally converged amount of strain and aging time. 11. As a method for determining strain damage and deterioration from magnetic properties, a certain amount of strain is assumed for the measured Barkhausen noise spectrum, and the best value for the Barkhausen noise spectrum measured from the aging database at that strain amount is Select the closest Barkhausen noise spectrum, determine the aging time, and then, based on this aging time, select the Barkhausen noise spectrum that is closest to the Barkhausen noise spectrum measured from the database of strain amounts at this aging time. Then, a new amount of strain is determined, the above method is repeated using the amount of strain as a reference, and the strain damage and deterioration of the measured object are determined by the finally converged amount of strain and aging time. A method for detecting deterioration damage in metal materials. 12. As a method of determining strain damage and deterioration from magnetic properties, magnetism and damage are determined in advance through statistical processing from data such as coercive force, residual magnetism, and magnetic hysteresis loop area of measured B-H characteristics. A method for detecting deterioration damage in metal materials, characterized by determining strain damage and deterioration of a measuring object using a database of deterioration and deterioration. 13. In claim 3, when measuring the magnetic characteristics of a wall such as a reactor pressure vessel, an excitation coil and a drive device for scanning a magnetic sensor are disposed on the inner wall and the outer wall, respectively,
A deterioration and damage detection device for metal materials, characterized in that an excitation coil is disposed on an inner wall and a magnetic sensor is disposed on an outer wall, or a magnetic sensor is disposed on an inner wall and an excitation coil is disposed on an outer wall. 14. In claim 3, when measuring the magnetic characteristics of piping, an excitation coil and a drive device for scanning a magnetic sensor are arranged inside the piping and outside the piping, respectively, and the excitation coil is placed inside the piping and the magnetic sensor is placed outside the piping. A deterioration and damage detection device for metal materials, characterized by arranging a sensor or a magnetic sensor inside a pipe and an excitation coil outside the pipe. 15. When detecting using the deterioration/damage detection device according to claim 1, future damage and deterioration of the measurement object is determined based on the data of the measured damage and deterioration of the measurement object and the database of equipment for the measurement object. A method for detecting deterioration damage in metal materials, characterized by having a function of predicting progress from a deterioration database. 16. In claim 1, the screen of the display device that displays the state of damage or deterioration of the measuring object is divided into a plurality of parts,
Displays the measurement conditions and measured magnetic properties, the operating environment and material data of the device being measured, data on determined damage and deterioration, and predictions of future damage and deterioration of the device. A deterioration damage detection device for metal materials, characterized in that it is equipped with a functional section that allows data to be entered and corrected using a keyboard or the like, and that allows for re-correcting judgments and calculations.